Miniature nuclear reactor designed for use on other planets

Kate Taylor, 30th August 2011

Engineers from NASA and the US Department of Energy (DOE) are working on a suitcase-sized nuclear reactor for use on the moon and other planets.

While previous missions have been powered by solar power and fuel cells, nuclear power has the advantage at greater distances from the sun, and in locations such as canyons and caves. But transport requirements mean it needs to be small.

"People would never recognize the fission power system as a nuclear power reactor. The reactor itself may be about 1 ½ feet wide by 2 ½ feet high, about the size of a carry-on suitcase. There are no cooling towers," says James E Werner of the DOE’s Idaho National Laboratory.

"A fission power system is a compact, reliable, safe system that may be critical to the establishment of outposts or habitats on other planets. Fission power technology can be applied on Earth's Moon, on Mars, or wherever NASA sees the need for continuous power."

The team's working to build a technology demonstration unit next year.

"The biggest difference between solar and nuclear reactors is that nuclear reactors can produce power in any environment," says Werner.

"Fission power technology doesn't rely on sunlight, making it able to produce large, steady amounts of power at night or in harsh environments like those found on the Moon or Mars."

He says that a fission power system on the moon could generate 40 kilowatts or more of electric power, about the same amount needed to power eight houses on Earth.

"The main point is that nuclear power has the ability to provide a power-rich environment to the astronauts or science packages anywhere in our solar system and that this technology is mature, affordable and safe to use," he says.

The main components of the system are similar to those found in the commercial reactors currently in use: a heat source, power conversion, heat rejection and power conditioning and distribution.However, there are a number of differences.

"While the physics are the same, the low power levels, control of the reactor and the material used for neutron reflection back into the core are completely different," Werner said. "Weight is also a significant factor that must be minimized in a space reactor that is not considered in a commercial reactor."